ideola

Now Available for ALL 928s!
In January, we organized a group buy for Stage8 locking CV bolts for the 924-944-968 platform. It was a HUGE hit, to say the least, with 110 participants in the first round. We are now launching a second round group buy, and are very pleased to announce the availability of locking CV bolts for the entire range of 928s (as well as all 914s and 911s)! This group buy will run from now through 15 April 2010.

Sizes and Fitment Notations
On the 928, there are two different sizes of OEM bolts: M10x57 and M10x50. Additionally, the early cars require 24 bolts, while the later cars require only 12 bolts. Regarding the M10x57 bolts, the cost of manufacturing odd-increment size bolts is not justifiable (according to Stage8), so there are two options available for these cars: M10x55 or M10x60 bolts. On my Euro-spec 1980 928, I had no fitment issues using the longer bolts, but I will leave it up to each purchaser to determine which application they prefer. I've put together a convenient application guide to allow you to easily identify the best option based on the model year of your car. For our group buy, we are limiting the clip and retainer configuration to Stage8's recommenation: the D-style clip (best abutment fitting to the CV boot flange) and the snap ring retainer (full circle engagement eliminates any concern about the retainer flying off at high speed). If you have any questions about what to order, don't hesitate to contact me via PM.

Pricing
MSRP = $118 per set of 24 bolts, clips & retainers / $59 per set of 12 bolts, clips & retainers
Group Buy discount = 25% off MSRP
Group Buy Price = $88.50 per 24 / $44.25 per set of 12
Shipping*: US = $6; Canada = $12.45; ROW = $14.45
*Note: Shipping is via USPS priority mail small flat rate box. We can fit up to two full sets in one box; add'l quantities will result in slightly higher shipping costs.

Ordering
I have set up a special application guide and group buy ordering page on my website:
To order => http://garage.ideola.com/prod-Stage8-GB.html
Please order through this page if possible. Otherwise, send me a PM with the details of your order and I will invoice you via paypal.

Specifications
• Bolts Are Aircraft Quality Grade 12.9 – 4130 Alloy Steel
• Retainers are 5052-H32 Polished Aluminum
• Snap Rings & Clips Are Spring Steel

Background & Product Details
For those that missed the first round, here is a repeat of the details. I worked with Stage8 to develop a locking CV bolt kit for the entire range of 924-944-968 cars. It was such a huge hit, that some 911 and 928 rennlisters contacted me about offering these for their cars too. I did quite a bit of research to investigate all of the permutations across these cars, and came up with 4 additional bolt sizes to accommodate the entire range of 911 and 928 cars, which Stage8 is now geared up to produce. This is truly a brand new offering, never before available for our cars!

Depending on model year, the 928 applications utilize twenty-four or twelve M10 cheesehead bolts to attach the half shafts at the transaxle stub axles and the outer hubs (six bolts per CV joint). As many of you know, the cheese head bolts are a royal PITA to deal with and will strip out if you're not careful. And for track driven cars, there have been multiple reports of the bolts backing out mid-session with catastrophic results. Many guys are safety wiring their bolts, and this was the approach I was planning to take on my UWB project until a 924board member mentioned Stage8 (for a header bolt application).

The Stage8 system utilizes their patented "GrooveLok" bolt, which has a 12-point head and a special groove in the head. Once the fastener is torqued down, any number of clip shapes are available, which lock onto the 12-point bolt head, and are then retained using either an E-clip or snap ring. Here are some photos using the samples they sent to me installed on a late offset 944 CV joint, boot, and outer stub axle:

Sample M8x65 GrooveLok bolt (the standard 928 size would be M10x50, M10x55 or M10x60)


Teardrop and D-Style clips; snap ring and E-style retainers


D-style clips installed, E-style retainer on left, no retainer on the right (I didn't have a snap ring plier handy when I made these photos)


Teardrop retainers installed (again, no snap rings, but they would normally have the snap rings installed)


Questions? Interest? Let me know!

Ducman82

thats not a bad idea. i used there header bolts on my old big block dart. i have had them back out once already. so count me in

hans14914

So when would these be shipping out?

Ducman82

good question.

ideola

Ducman, got your PM on the pricing. I made a mistake and listed the 944 group buy price. The 928 M10 bolts are MSRP$118 for a set of 24. The group buy price should have been listed at $88.50, which is 25% off of the MSRP. The $79.50 price is the 944 discounted pricing for 24 M8 bolts. Sorry for the confusion, I've corrected it above.

Regarding shipping, Stage8 is now ramped up for production on these, and there is no minimum order, so what I will probably do is batch these up in groups of 20 orders, rather than bombard them with 100+ orders all at once. This will help the early participants get their parts sooner, and will help Stage8 manage their production cycle. Lead time from time of order being placed with Stage8 is about two weeks.

Sorry it's not a direct answer, but if participation is as brisk as it was last time, I would expect to be placing orders with Stage8 once per week, with delivery occurring about 2 weeks following. Does that make sense?

jon928se

Those look nice, but I've never heard of CV bolts coming loose on a 928 unless they weren't installed correctly.

ideola

While I haven't researched the problem as thoroughly on the 928 platform, the CV design is essentially identical to the other applications that do have well-documented failures. Particularly in track use. Overkill for the street? Maybe. Cheap insurance for the track? Definitely. And WAY easier than safety wire. I'd be surprised to find out that track-prepped 928s were running without safety wire on their CV bolts.

FWIW, this is not a problem unique to Porsches; Stage8 makes CV kits for other platforms that have the same problems...it's just that our inquiry is what got the ball rolling on the 924-944 stuff, and it just took off from there.

The thing to remember is that for ALL of the OEM applications, stretch bolts are used, and therefore require new replacements after EACH time the bolts are "de-torqued". On a track car, that is less than practical, even if the cost of OEM bolts is less than $1 each; just the nuisance of having to have a ready supply sitting around. These bolts are NOT stretch bolts, and are therefore re-usable. Even if you're not convinced of the failure risk, the simple convenience of being able to reuse the bolts and not have to mess with safety wire seems compelling enough to make these worthwhile.

As best I can tell, failures are due to a two primary issues: 1) re-use of OEM bolts (which one could argue constitutes improper installation); and 2) contaminated threads on either the bolts or the stub axles (CV grease is not conducive to maintaining torque). So unless you're working in a "white room" type environment, there is a fair chance that the threads will be contaminated, particularly in a pit environment. Once an OEM bolt loses torque, either from being stretched or from grease contamination, it (and it's neighbors) will inevitably back out. Some will fall out entirely, and some may snap off due to the increased load. I don't see anything in the 928 design that makes it any less susceptible to these failure modes than the other cars.

Fabio421

Have you checked yours? It's actually pretty common for these to come loose. There was even a thread about is recently from Tampa 928s but I can't find it.

Good product I just saw these fasteners featured on a show on SpeedTV last weekend.

borland

The 928 needs these on the engine oil pan bolts. Can they be purchased for on M6 hex head bolts?

ideola

We can get pretty much anything we spec out. M6 is getting pretty small, but I'm pretty sure we can still get bolts in that size Here's what we'd need to figure out:

Length and thread pitch of the OEM bolt (shank only, not including the head)
Is there a sufficient surface for the D- or Teardrop clips to abut against?
How many bolts are required?
How many permutations are there across the model years?

This requires some investigation in PET, which I'm happy to do, but it may take me a week or so to wade through all the info. We're already looking into other applications on the 931 & 944 (fuel rail, shift linkage, exhaust mani & turbo locking nuts).

I'll check in tomorrow re: the M6 size just to make sure they're available before we get to deep into research mode Thanks for the suggestion, and feel free to post other ideas. I have no problem doing the legwork if there's a real need.

Ducman82

ordered my set!

GregBBRD

I've never seen a C/V bolt, on a street car, which was properly torqued, loose.

I have seen them come loose on track cars....but never when using the "double" plate system the factory uses on the GT-3 race cars.

These are cool looking, however!

Bill Ball

Interesting. The 928 factory WSM does not indicate to replace these bolts, although in the same page it notes three nuts on far less critical parts should be replaced. There are several sections in the WSM that discuss axle removal and re-installation that were re-written over the years, and they all simply comment to torque these bolts to 83Nm. I was not aware these are stretch bolts that are deformed by the torque, and none of the 928 specialty service shops I have used or know have ever mentioned this before. Mine are original and the axles have been off several times to rebuild them or change the wheel bearings.

GregBBRD

Yes, that is complete BS. Not even the factory race cars have instructions to replace the bolts...and they suggest replacing almost everything every 40 hours.

ideola

To be quite transparent with you, I have NOT poured through every page of every FSM for every model to acquaint myself with the service recommendations, even though I own a 1980 Euro Shark (along with 7 924 variants). So on the point of familiarity with 928 FSM, I will concede.

As to the "complete BS" comment, on a personal level, I don't appreciate the implication. I don't mind a civil discussion about the relative merits, but also don't appreciate being called a BSer.

What I can tell you for sure is that I have had owners of 914s, 911s, 924s, 944s, 951s, 968s and YES, even 928s, send me emails or PMs of anecdotes about loose CV bolts, some of them more catastrophic than others. So it is most definitely a pervasive problem that is not isolated to one model or another. It is also not isolated to Porsches, as the locking CV bolts were developed by Stage8 for other platforms first. So FSM recommended or not, I still believe these bolts are good idea. Overkill for a bone stock street-driven car? Probably! Cheap insurance for performance-modified or track-driven car? You bet!

You can argue all you want about "proper torque and installation", but unless you're working in a "white room" environment, I find it highly unlikely that CV bolts could be installed without some significant risk of contaminating the threads with grease. Are there ways to mitigate that? Sure...flushing the bolts and threads with part cleaner is one way! In my opinion (and apparently the 120+ participants we've now had in the group buy), using an affordable, easy-to-install product like these is another way.

To be clear, I'm not trying to be argumentative, simply pointing out that while these may not be for everyone, they are still a Really Good Idea for some applications. Including the 928.